1. Field of the Invention
The present invention relates to a method for manufacturing a liquid discharge head that discharges liquid, and an ink jet recording head that discharges ink to a recording medium for recording.
2. Description of the Related Art
A liquid discharge head for discharging liquid can be applied, for example, to an ink jet recording process in which ink is discharged to a recording medium for recording. An ink jet recording head (hereinafter referred to as a recording head) has a substrate equipped with a plurality of discharging ports from which ink is discharged, a flow path that communicates with each of the discharge ports, a supply port for supplying ink to the flow path, and an energy generation element that adds discharge energy to the ink in the flow path at minimum. A substrate made of silicon (Si) is normally used.
A method for manufacturing such a recording head is discussed in U.S. Pat. No. 5,478,606. The method for manufacturing the same on a substrate in which the energy generation elements are formed, includes steps of 1) forming a flow path pattern with a soluble resin, 2) forming a coating resin layer on the soluble resin layer, which will serve as flow path walls, by solving in a solvent a coating resin containing an epoxy resin that is solid at ordinary temperatures and then solvent-coating the solution on the soluble resin layer, 3) forming discharge ports for discharging ink to the coating resin layer over the energy generation elements, and 4) eluting the soluble resin layer.
Meantime, aluminum (Al) is used as a wiring material for supplying electric power to the energy generation elements in the recording head.
Aluminum (Al) is a common material used as a wiring material for semiconductor elements. A film is formed by a vacuum film forming method such as sputtering and vacuum evaporation, and a wiring pattern is formed by dry-etching and wet-etching, using a resist pattern as a mask.
Recording heads in recent years tend to be manufactured with a greater number of energy generation elements to accelerate printing speed. A number of power supply wirings thus increases, which causes the recording heads to expand their overall width. Since the length and area of the recording heads increase at the same time, these requirements cause increases in manufacturing costs and size of a recording apparatus.
In order to solve such a problem, a power supply wiring with thicker film thickness can be formed on a substrate instead of expanding the width in order to reduce wiring resistance. However, the aforementioned wiring formation (a power supply wiring with thicker film thickness) needs a heavy load in manufacturing.